This invention relates to extinguishing fires in a mine or other subterranean environment of solid natural material. In particular, this invention relates to means for isolating the fire and extinguishing it using high expansion foam.
High expansion foam is a proven and effective means for controlling and extinguishing fires in mines.
Under certain circumstances, especially when the fire is in an upward sloping passage from the foam generator, it is necessary to construct a partition or seal to separate the foam generator from the fire site. The partition prevents the high expansion foam from flowing back toward and engulfing the foam generator.
Current practices involve the construction of a partition to isolate the foam generator from the passageway which contains the fire. Concrete block, wood framing, plastic sheeting, brattice, or similar materials have been used for such partitions. Passageways often have irregular dimensions to which a partition must conform to avoid leakage around the periphery of the partition. Construction of such partitions is a time consuming process.
After the partition is made, a hole must be cut through it to allow passage of the high expansion foam from the foam generator to the fire site. Cutting a hole in the partition can be a labor intensive, time consuming, and dangerous process, depending on the construction materials, and often results in a partition with substantial leakage around the high expansion foam feed tube.
U.S. Pat. No. 3,831,318 discloses stored mine passage barriers formed of inflatable bags. Such bags are inflated with combustion suppressing agent when an explosion is detected by associated sensors.
U.S. Pat. No. 4,023,372 discloses flexible barriers used to close a mine passage having a gas-inflated peripheral portion which enables the barrier to conform to the walls of the passage. A web extending from the peripheral portion closes the passage. The web has a passage closed by a zipper.
U.S. Pat. No. 4,102,138 discloses a flexible portable barrier used to close off a mine gallery consisting of a flexible bag which is initially inflated with a gas and subsequently filled with hydraulic cement. The barrier has a crawl tube which extends through the barrier and may be closed with a cover.
U.S. Pat. No. 5,188,186 discloses a flexible expandable barrier stored in the ceiling of a mine. In response to a stimulus detected by a monitor, a foam-like material fills the barrier, causing it to extend and isolate the mine entry. A closable opening or flap allows passage through the barrier.
These prior art inventions do not fulfill the need for a portable, rapidly deployed partition or seal having means for passage of a feed tube from a high expansion foam generator.